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HMRC internal manual

Enquiry Manual

SA Surcharge: Amounts and Calculation


TMA70/S59C only applies to the 2009-10 tax year, and any previous tax year.

See CH155000+ for 2010-11 and subsequent tax years

There are two surcharges; these are calculated as a percentage of the tax/NICs that have become payable and which remain unpaid at two particular points in time:

  • S59C(2) charges 5% of the tax/NICs unpaid on the day following the expiry of 28 days from the due date.
  • S59C(3) charges another 5% on the tax/NICs unpaid on the day following the expiry of 6 months from the due date.

The 31 January in-year and 31 July after-year payments on account do not carry surcharge for late payment. However, any part of POAs for a tax year that have not been paid by the following 31 January will fall into the (S59B) balancing payment at that date and the total unpaid balance does carry surcharge.

It is crucial to identify the actual due date for the particular tax/NICs in question, and not to think in terms of a “normal due date” or “usual due date” or any other generality.

Tax/NICs can become due and payable by various routes

  • a self-assessment (by a return being “processed”)
  • a “taxpayer amendment”
  • a “correction”
  • a “jeopardy” amendment during an enquiry
  • a “closure” amendment at the end of an enquiry
  • a “discovery” assessment S29 TMA
  • an amendment following determination of an appeal against any of the last four.
  • an “HMRC” determination S28C,

and the due date will vary accordingly.

Also S55 postponement applications with appeals can have an effect on what is due when.

For this reason, we use the term “trigger date” for the date at which a surcharge is triggered on a particular amount of unpaid tax/NICs. EM4105 sets out detailed guidance.